KR100424792B1 - a - Google Patents

Abstract

The present invention relates to a test method and a structure of a pulse gun, which is an artificial disturbance supply device, for a combustion stability confirmation test which should be verified in the development of a rocket engine.

A pulse gun with a connection bolt connected to the front, plugged with a membrane, and having an explosive part including an initiator and an electrical supply in the back of the internal charge gun cavity;

The pulse gun pressure wave inlet is formed in the pulse gun adapter to which the pulse gun is connected, and is composed of a pressure wave induction apparatus in which an adapter for nitrogen purging and an engine adapter are installed in the common induction common.

Description

Structure for Rocket Engine Combustion Stability Evaluation {a}

The present invention relates to a test method and a structure of a pulse gun, which is an artificial disturbance supply device, for a combustion stability confirmation test which should be verified in the development of a rocket engine.

The combustion instability of rocket engines occurs during the development of almost all rocket engines and can cause fatal damage to the operation of the engine itself and the entire vehicle system.

Combustion instability is caused by the mutual coupling of the combustion process and the flow in the combustion chamber, and it is known that the energy supplied from the combustion process is caused by amplifying the pressure and velocity of the flow field in the combustion chamber.

That is, in order to prevent combustion instability, the pressure and velocity oscillation of the flow field (or acoustic field) inside the combustion chamber should not be increased.

The most commonly used technique for evaluating the combustion stability of a rocket engine (SRT) is the use of a bomb or pulse gun to generate artificial disturbances such as Figure 1 during the combustion process. The combustion stability of the engine is evaluated by determining whether the pressure vibration in the combustion chamber is divergent or attenuated.

In addition, there is a method of artificially disturbing the supply pipe of fuel or oxidant, but this is used as a secondary stability evaluation technique.

In the case of chestnut, which has been widely used as a combustion stability evaluation technique, chestnuts are installed directly in the combustion chamber of the combustion chamber and are exposed to high temperature / high pressure flow during the combustion process, making it difficult to predict the melting point of the material surrounding the initiator It is difficult to set the disturbance point.

On the other hand, since the pulse gun is installed on the outer wall of the combustion chamber and is not directly exposed to the high temperature / high pressure combustion gas, and generally uses an electric ignition method, it has an advantage of supplying artificial disturbance at a desired time during the combustion process.

Accordingly, the pulse gun is the most widely used in the stability evaluation technique that is commonly used recently.

Although the combustion stability evaluation technique is an essential core technology that must be preceded in the rocket engine development process, it has not been developed in Korea due to the avoidance of technology transfer in advanced countries.

In developed countries, the development of rocket engines goes through dozens or hundreds of combustion stability verification tests, followed by the engine life test.

In Korea, only a limited number of artificial pressure wave disturbance techniques are used. However, there are no experiments in connection with the combustion phenomenon of the engine.

However, in the case of pulse guns, the thermal considerations are somewhat less than in the case of nights, but the difficulty in designing / manufacturing such as high temperature / high pressure gas is likely to flow in the direction of pulse gun exit and generates pressure wave of desired intensity. It has

In addition, since the production cost and the combustion test cost of the single-life rocket engine is quite expensive, it is also necessary to sequentially control several pressure waves at a time interval in a single combustion test.

The present invention provides a method and structure for manufacturing a pulse gun, which is an artificial disturbance supply device, for a combustion stability confirmation test, which should be almost inevitably verified when developing a rocket engine.

Through this, it is possible to save time / cost due to trial and error in the development of rocket engine, and to develop an engine with high stability and reliability.

The present invention can reduce the cost of rocket engine testing and development by providing a device / testing technique that can provide more than two artificial excitations, as well as response characteristics of the engine by a single magnitude pressure wave in a single combustion test.

This could be used as a technique to verify the instability characteristics of low-pollution gas turbine combustors, which are becoming a big issue in developed countries as well as rocket engines in the future.

1 is a schematic view of the test method of the present invention

Figure 2 is a cross-sectional view of the pulse gun of the present invention

Figure 3 is a plan view of the pressure wave induction apparatus of the present invention

Figure 4 is a front view of the pressure wave induction apparatus of the present invention

Figure 5 is a side view of the pressure wave induction apparatus of the present invention

6 is a connection state of the pressure wave induction apparatus and the pulse gun of the present invention

Perspective view

[Description of Symbols for Main Parts of Drawing]

1: membrane 2: connecting bolt

3: Claim 4: Electric supply unit

5: airtight part 6: fixing pin

7: electrical connector 8: pulse gun cavity

9: initiator 10: airtight part fixing part

11: cavity for induction 12: membrane trajectory

13: pulse gun adapter 14: pulse gun pressure wave inlet

15: nitrogen for purging 16: adapter for nitrogen purging

17 engine adapter 18 pulse gun pressure wave trajectory

19: induction cavity hemispherical shape 20: pulse gun

30: pressure wave induction device

The present invention is the configuration of the pulse gun 20 that can generate a pressure pulse at a desired time and the pressure wave induction device 30 to efficiently install the pulse gun 20 in the rocket engine to perform the combustion stability check test Provide test methods and structures for

The pulse gun 20 may be divided into an explosive part 21 capable of applying an instantaneous pressure through the gunpowder and a configuration inducing the pressure to the pulse gun 20.

The pulse gun 20 is a membrane (1) is installed in front of the pulse gun cavity (8) and the connecting bolt (2) is installed so that it can be connected to the outside.

The explosive part 21 is stored therein the drug (3), the one side is composed of the initiator 9 and the electricity supply (4).

An airtight part 5 and a fixing pin 6 are installed at one side of the electric supply part 4 so that the fixing and airtightness are maintained through the airtight part fixing part 10, and the electric connector 7 is supplied to the inside to one side. Will be installed.

The explosive portion 21 is composed of an initiator 9, an electricity supply 4 for igniting the initiator, and an antistatic agent 3 for generating the main explosion force by the explosion of the initiator 9.

That is, the explosive force supplies a pulse signal of a predetermined voltage / current to the electric supply unit 4 to explode the initiator 9, and the explosive agent 3 explodes by this explosive force to generate a strong pressure instantaneously.

This pressure causes the high pressure gas to fill the pulse gun cavity 8 in the pulse gun 20, which breaks the membrane 1 and transmits an instantaneous pressure wave towards the combustion chamber.

At this time, the pulse gun cavity (8), the anti-inflammatory drug (3) and the detonator (9) all act as a cavity filled with high-temperature / high pressure gas, which causes the airtight portion (5) and the fixing pin (6) to the side. It is very important to keep this part tight because strong pressure is transmitted backwards.

Airtight portion (5) to reduce the impact by using Teflon and chaklite, the fixing pin (6) is to act to prevent mechanical rotational force and thrust.

The connecting bolt 2 couples the pulse gun 20 with the pulse gun adapter 13 of the pressure wave induction device 30, and serves to compress the membrane 1.

In addition, it is possible to adjust the magnitude of the excitation pressure applied to the engine by adjusting the filling amount of the anti-pill 3 of the pulse gun 20.

Membrane 1 is installed to a thickness of 1mm of aluminum material to protect the explosion unit 21 from the high temperature / high pressure gas that can be introduced from the combustion chamber and at the same time serves to introduce the pressure wave toward the engine.

The pressure wave induction device 30 for efficiently applying the pulse gun 20 as described above to the rocket engine combustion test is shown in FIG. 3.

This effectively prevents the inflow of combustion gas in the engine and the pulse gun adapter 13 formed with the pulse gun pressure wave inlet 14 coupled to the connecting bolt 2 of the pulse gun 20, thereby causing malfunction of the pulse gun 20. Nitrogen purging adapter 16 for preventing the engine, the engine adapter 17 for introducing a pressure wave into the engine and the induction cavity 11 is composed of.

Membrane caused by the explosion pressure inside the pulse gun 20 by treating the shape of the induction cavity 11 in the pressure wave induction device 30 in a direction opposite to the pulse gun adapter 13 to a hemispherical shape 19 in the induction cavity. A fragment of (1) collides in the guiding cavity 11 with the membrane trajectory 12 as shown by the arrow in Fig. 3, and a large amount of momentum decreases.

In addition, by bending the outlet direction of the pulse gun 20 and the outlet of the engine adapter 17 by 90 degrees, this will not damage the engine combustion chamber wall as the momentum is already greatly reduced when the debris flows into the engine. .

By designing the induction cavity 11 of the pressure wave induction device 30 in the shape as shown in FIG. 3, damage caused by debris that may be applied to the wall of the combustion chamber can be minimized.

In addition, by installing two or more of the pulse gun adapter 13 with the inclination like the pulse gun pressure wave inlet 14, the high-pressure / high temperature pressure of the pulse gun 20 that is pre-exploded when generating the pressure wave at a time interval By not directly exposed to the wave serves to protect the pulse gun 20 to be exploded.

Since the artificial disturbance timing of the pulse gun 20 should be carried out when the combustion of the engine is stabilized or before the ignition is stabilized after ignition as shown in FIG. 1, the high temperature / direction toward the pressure wave induction device 30 and the pulse gun 20 is performed. As the high-pressure combustion gas is introduced, the pulse gun 20 may be exposed to high temperature, thereby causing an explosion due to the characteristics of the initiator 9.

In order to prevent such an explosion of the pulse gun 20, a nitrogen purging adapter 16 is installed in the pressure wave induction device 30, so that nitrogen is higher than the combustion chamber pressure before the engine is ignited (about 5 atmospheres higher than the combustion chamber pressure). By supplying with the purging nitrogen 15 of FIG. 4, the high temperature / high pressure gas from the engine is prevented from flowing into the pressure wave induction device 30 and the pulse gun 20.

When the pulse gun 20 is ignited at a predetermined point in time, a pressure wave such as the pulse gun pressure wave trace 18 of FIG. 4 is applied to the pressure wave induction device 30 because a pressure considerably higher than the pressure due to nitrogen purging is applied. Is applied to the engine.

The present invention provides a technique for manufacturing a pulse gun that can reliably provide artificial disturbance to evaluate the combustion stability during combustion of a rocket engine, and to provide a pressure wave induction device for an effective experiment in actual engine combustion test.

By using the present invention it is possible to reduce the trial and error associated with the development of the engine, and in particular, by introducing the pressure wave induction apparatus efficiently to provide an advantage that can be carried out several times in a single combustion test combustion evaluation.

Claims (6)

The connection bolt 2 is connected to the front and is blocked by the membrane 1, and the explosive part 3 is stored in the internal pulse gun cavity 8, and the backside is composed of the initiator 9 and the electricity supply 4. A pulse gun 20 having 21, The pulse gun pressure wave inlet 14 is formed in the pulse gun adapter 13 to which the pulse gun 20 is connected, and the nitrogen purging adapter 6 and the engine adapter 7 in the induction common 11 therein. ) Is a structure for rocket engine combustion stability evaluation, characterized in that consisting of a pressure wave guide device (30) is installed. 2. The structure for rocket engine combustion stability evaluation according to claim 1, wherein the membrane (1) is made of aluminum of about 1 mm. The airtight portion 5 behind the initiator 9 according to claim 1, in order to maintain the airtightness of the engine when the instantaneous hot / high pressure gas generated in the pulse gun cavity 8 is delivered to the rear of the pulse gun 20. The structure for rocket engine combustion stability evaluation, characterized in that to reduce the impact by installing a fixed pin (6) is installed to prevent rotational force and thrust. The method of claim 1, wherein the adapter for the pulse gun 13 is provided so as to prevent damage to the combustion chamber wall caused by fragmentation of the aluminum membrane 1 which breaks during the explosion of the pulse gun 20, and to supply two or more pressure pulses to the combustion chamber. A structure for evaluating combustion stability of a rocket engine, characterized in that a plurality of installation. The method of claim 1, wherein inert pressure nitrogen is introduced into the pressure inducing device 30 before the combustion test in order to prevent the explosion of the pulse gun 20 due to the inflow of high / high pressure engine combustion gas before the explosion of the pulse gun 20. A structure for evaluating combustion stability of a rocket engine, characterized by purging at atmospheric pressure above the combustion chamber pressure. The structure for evaluating combustion stability of a rocket engine according to claim 1 or 4, characterized in that the pulse gun adapter (13) projects obliquely outward.